Protractor



Patented nlune 24, 1924.

GUsrAvn van DE veran, or WATERTOWN,livrassacnnsn'rfrs.'

PROTRAC'TOR.

Applicatin filed September 25., 19722; Serial No.`590,3e8;`

To all whom it may concern:

Be it known that I, GUSTAVE VAN Dn VEIRE, a citizen of the United States, residing yin Watertown, inl the county of Middlesex and State of Massachusetts, have invented an Improvement in Protractors, of which the followingis a specification.

This invention relates to Yand has torits object to provide a protractofr adapted 'for use especially by both'draftsmen and machinists and`arranged to give bothobtuse and acute angles on opposite sides thereof.

A further object is vto providea protrae'- tor and attachments therefor by which the protractor may be supported in a vertical position for the laying out and measurement of vertical angles.`

A` further object is generally to 'improve the construction and extend and facilitate the use of protractors. n i

Fig, 1 is a plan view of a protractor embodying the invention.

FFig. 2`is a side elevation, in detail, of

ig. 1. n

Fig. 3 is a plan view of the pro-tractor with the blade at'the outer edge of the base plate.

Fig. 4: is a plan view illustrating more particularly an attachment secured to an edge of the base plate by which the protractor may7 be supported in a vertical position.

Fig 5 illustrates, in side elevation, a protractor having attachments by which it may be supported above abase plane for the measurement of angles, the sides of which do not coincide with a side of the base plate of the protractor.

Fig. 6 is an end view of Fig. 5. c Y

`F ig. 7 is a sectional elevation alongline 7-7 of Fig. 5;

Fig. 8 is a sectional detail through the rotatable disc, taken along line 8 8 of Fig. 1, and illustrating theclamping means Jfor the adjustable blade.

Fig. 9 is. a sectional detail through the clamping means of the attaching-member taken along line 9-9 of Fig. 1.

AsV here shown, the protractor embodying my invention includes a Hat base-plate 10 having parallel opposed side edgesll and the end edge 12 arranged at right angles to said side edges. Said plate is. also formed with the` openings 13 and 14 the side walls of which are or may be substantially parallel to the corresponding edges 11 and 12 ot of said plate 10 and is, in effect, integral or rigid withv said plate. Said stud is formed with an enlarged cylindrical bearing member or hub V16b which is adapted to support said disc k17 rotatably and, for thispurpose, said dise may be formed with a recess 18 in its under tace in which said hub 16b is received. The depth v'of said recess is adapted to be slightlyless vthan the' height of said hub whereby the discis clear of the baseplate and is'supported" upon the top flat face of said hub. Theside wall ot said hub and recess are adapted to-(be a .good fit whereby the disc'ma-y 'bejaccurately supported rotatably against lateral displacement. Said stud is ork may be also formed or provided with a: reduced cylindrical extension 16c which projects through and is .a rotatable tit infanV aperture in saidfdisc 17. Said stud is also formed with a threaded upper endportion 16d on 'which a thumb nut 19 is received and Asaid nutserves toyclaimp said disc in viiXed posit-ion to the base plate 10 or re- L lease it for rotary movement thereon.

s. washer 20 may beinterposed between said Vdiscv and thumb nut and said washer may be locked against rotation on said stud', it desired, in` any suitableV manner 'not necessarily shown.

The periphery of said rotatable disc 17 is 0r may be beveled to Vprovide a relatively thin lower edge adapted to pass adj acentthe degreev graduations carried by said baseplate 10, and a Vernier 21 may be carried by saidY disc at its periphery and 'coperate with said degree'graduations to permit the reading of angles to within less than one degree.

Said disc is or may be formed or provided with an extension 22 opposite said Vernier 21 and said extension may be recessed to providea seat 23, Fig..8,"for an adjustable blade; and said seat is or may be arranged to be perpendicular to a line passed through the center of said stud 16 and the center of the Vernier. A blade 24 is adapted to be received in the recess in said disc-extension and above the base-plate. Said blade may be provided with a slot 25 extended from end to end ot it and a clamping member 26 is adapted to enter said slot and serves to clamp said blade in adjusted position to said disc 17.

An eccentric clamping lever 27 may actuate said clamping member in a more or less customary manner. l

Said disc 17 with its blade 24 is adapted to rotate throughout a complete circle and angles may be laid out and measured with the blade 24 in position between the pivot s tud 16 ot the disc and the body of the base plate, as illustrated in Fig. 1, and also when the blade is in a position beyond the pivot stud and the body of the base plate, as illustrated in Fig. 3.

When the protractor, as so far described, is used, by draftsmen, for instance, to lay oli angles on a surface, the blade 24 is raised above the surface by a distance at least equal to the thickness of the base plate, and thereby prevents the accurate drawing of lines inasmuch as there is no barrier to prevent the point of the pencil, or equivalent, 'from being moved unintentionally under the blade, ln other words, the pencil can not be guided accurately unless the blade is in direct contact with the paper or other surface on which the line is to be traced. In accordance with an object or" my inven# tion, I provide means which operates, in etect, to extend the edge of the blade 24 to the lower tace of the base plate, whereby to close the gap between the blade and a surface on which the protractor may be placed. Said means includes an attaching member 28, Figs. 1, 2 and 9 which has a flat face 29 of substantial width. Said member is or may be formed with a groove 28a in which the edge of said blade 24 is adapted to be received and said member may be provided with a clamping-member 29il which is adapted to engage the opposite edge ot said blade, whereby to clamp said attaching-member in adjusted position on said blade. Said clamping member may be actuated by means including the thumb nut 29b in any suitable manner. Said attaching member is or may be formed with the bevelled end portion 28b whereby said member may be moved directly in contact with an edge of the baseplate and provide a definite boundary for the angle included between the edge ct said base-plate and the face of the attaching member. The face of said attaching-inember is adapted to depend below the blade 24 and be substantially flush with the lower face of the base plate.

Said attaching-member 28 is also adapted to be clamped Iremovably to the edges 11 and 12 of the base-plate, as illustrated in Figs. 1 and 4, and the flat face 29 thereof provides a substantial support on which the protractor may rest for the laying out and measurement of vertical angles.

lVith the usual type of protractor it is sometimes difficult to measure or lay out angles when the body of the protractor must be held in a fixed position, as is otten the case. In accordance with my invention, l provide means to accomplish this result. Said means includes a blade 30, Fig. 5, having a straight edge 31. Said blade is pivoted to one end of a link 32 and may be clamped in adjusted position thereto by means including the clamping nut 33. The other end of said link is pivoted to a supporting member 34 and may be clamped in adjusted position by suitable means including the clamping nut 35. Said supporting member 34 is adapted to be secured adjustably to an edge of the base-plate of the protractor by suitable means including the clamping nut 36. Said blade 3() is adapted to function in cooperation with the blade 24 for the laying out and measurement of angles in a manner which may be readily understood.

For many purposes it may be desirable to support the protractor in a vertical position at a substantial distance above a supporting surface. -For this purpose, l may provide a standard which includes the base block 40, which latter may have the il-shaped groove 41 therein by which the block may engage round or V-shaped supporting members, and the dat surfaces 42 by which the block may be supported on a plane surface. A cylindrical rod 43 may be secured to and extend perpendicularly above said block and may be provided with a vertically-adjustable supporting member 44 adapted to hold the protractor.

Said supporting member may include a clamping screw 45 by which said member may be secured in adjusted position on said rod, and an arm 46 which bears a lateral projection 47 having a clamping nut 49. Said projection is adapted to enter holes 48, Fig. 1, formed in the base plate of the protractor and secure it to the supporting member. Said arm 46 of the supporting member is or may be formed with an eX- tension 50 in which an adjusting screw 51 is threaded and said screw is adapted to bear against an inner edge of the protractor base plate and move it into a desirable position, in which position the protractor may be secured by the nut 49.

I claim:

1. A protractor having a base-plate formed with parallel side-edges and an endedge arranged at right angles to said sideedges and slots having edges arranged sube stantially parallel to said side and end-edges,

a disc pivotally supportedron said baseplate and rotatable throughout a complete revolution over a face of said base-plate, a blade carried by said disc, and co-registering degree indicia carried by said disc and base-plate.

2. A protractor having a base-plate, a disc pivotally supported on said base-plate and rotatable over the upper face of said base-plate, and a blade carried by said disc and movable therewith over the upper face of and adapted to extend laterally beyond said base-plate, said blade having a depending extension adapted to extend said blade substantially to the lower face of said baseplate.

3. A protraotor having a base-plate, a dise pivotally supported on said base-plate and rotatable over the upper face of said base-plate, and a blade carried by said disc and movable therewith over the upper face of and adapted to extend laterally beyondl said base-plate, said blade having an adjustable depending extension adapted to extend the edge of said blade substantially to the lower face of said base-plate.

4. A protractor having a base-plate, a disc pivotally supported on said base-plate and rotatable over the upper face thereof, a blade carried by said disc and movable there with over the upper face of said base-plate,

and an attaching-member adapted to be secured adjustably to said blade having a straight face of substantial length which is arranged to extend below said blade and terminate substantially in the plane of the low-er face of said base-plate.

5. A protractor having a base-plate formed with a relatively thin edge-face, a

dise pivoted on said base-plate, a relativelv y thin blade adj ustably connected to said disc, and a member having a relatively broad edge-face adapted to be secured to the edge of said base-plate and also to the edge of said blade.

6. A protractor having a base plate, a

disc pivotally mounted on the upper face of said plate, a blade carried adjustably by said dise and having an extension arranged to extend substantially flush with the lower face of said plate, a supporting member having means connecting it with said plate for adjustment along the length thereof, and a second blade pivotally connected to said supporting member having an end thereof arranged to extend over the side edge of and engage said base plate and also said firstblade.

7. A protractor having a base-plate, a disc pivotally carried by said base-plate, a blade carried by said disc and adapted to extend laterally of said base-plate, a second blade adapted to cooperate with said first blade, a link pivoted to said second blade, and a supporting member to which said link is pivoted having means for detachable connection with said base-plate.

8. A protractor having a base-plate, a disc pivotally carried by said base-plate, a blade carried by said disc and adapted to extend laterally of said base-plate, a second blade adapted to cooperate with said first. blade, a link pivoted to said second blade, and a supporting member to which said link is pivoted having means for detachable conneetion with said base-plate, and means to clamp said second blade in angularly adjusted positions relative to said base-plate.

9. A protractor having a. base-plate, a disc pivotally carried by said base-plate, a blade carried by said dise and adapted to extend laterally of said base-plate, a second blade adapted to cooperate with said first blade, a supporting member pivotally connected with said second blade, means detachably to secure said supporting member to said base-plate, and mea-ns to clamp said second blade and supporting member against relative movement.

In testimony whereof, I have signed my name to this specification.

GUSTAVE VAN DE VEIRE. 

